Falls are among the most common and serious health problems of the elderly. The current approaches to fall prevention focus on individual adaptation to existing conditions, or making changes in the home environment to decrease the likelihood of falling. While numerous studies have reported individual-level risk factors or home environmental hazards for falls of the elderly, neighborhood environmental factors have rarely been considered. The purpose of this proposed ancillary study is to determine the effect of neighborhood environmental attributes on rate of falls in a large population- based cohort of community-dwelling older persons being studied as part of an NIH- funded Program Project (AG04390-21A1). We propose to collect neighborhood environmental data in the census block groups where the cohort members reside. Environmental data that vary little over time, such as availability and accessibility features of sidewalks, parks or other outdoor places that elders visit during their daily activities, will be collected at the beginning of the study and monitored over the period of the Program Project. Environmental data that are more likely to vary over time, such as condition and maintenance of sidewalks and streets, will be collected every three months for the duration of follow-up. The neighborhood data will be integrated with the individual-level data collected by the Program Project using the Federal Information Processing Standards Codes (FIPS55) of census block groups of the participant. The primary goal of the study is to determine whether lower rates of outdoor falls, after adjusting for overall physical activity level, are associated with potentially modifiable environmental hazards (such as availability, good features and condition of sidewalks, walkable streets and outdoor parks and recreational areas, and good maintenance of outdoor parking lots and garages), and assess whether such associations are modified by the health status of the participant. This proposed study will help us better understand whether the built environments of urban neighborhoods meet the needs of their elderly residents. It will provide information that is directly relevant to design of potential community-based environmental interventions that modify or improve the living environment for an aging society, and may suggest ways to reduce medical costs related to falls. Such approaches are of paramount importance in an era when moderate physical activity is widely recommended to the elderly to maintain their physical function and independence and to reduce the risk for chronic diseases and disabilities. PUBLIC HEALTH RELEVANCE This proposed study will examine the effects of outdoor neighborhood environmental characteristics (e.g., limited availability and poor features and condition of sidewalks;lack of walkable streets;poor maintenance of outdoor parks and recreation areas) on risk of outdoor falls among community-dwelling older persons. The results of this study should suggest specific community-based environmental intervention strategies that could improve the living environment for our aging society. Such approaches are of paramount importance in an era when moderate physical activity is widely recommended to the elderly to maintain their physical function and independence and to reduce the risk for chronic diseases and disabilities.